#include <bits/stdc++.h>

#define _overload(_1,_2,_3,name,...) name
#define _rep(i,n) _range(i,0,n)
#define _range(i,a,b) for(int i=int(a);i<int(b);++i)
#define rep(...) _overload(__VA_ARGS__,_range,_rep,)(__VA_ARGS__)

#define _rrep(i,n) _rrange(i,n,0)
#define _rrange(i,a,b) for(int i=int(a)-1;i>=int(b);--i)
#define rrep(...) _overload(__VA_ARGS__,_rrange,_rrep,)(__VA_ARGS__)

#define _all(arg) begin(arg),end(arg)
#define uniq(arg) sort(_all(arg)),(arg).erase(unique(_all(arg)),end(arg))
#define getidx(ary,key) lower_bound(_all(ary),key)-begin(ary)
#define clr(a,b) memset((a),(b),sizeof(a))
#define bit(n) (1LL<<(n))
#define popcount(n) (__builtin_popcountll(n))

using namespace std;

template<class T>bool chmax(T &a, const T &b) { return (a<b)?(a=b,1):0;}
template<class T>bool chmin(T &a, const T &b) { return (b<a)?(a=b,1):0;}

using ll=long long;
using R=long double;
const R EPS=1e-9; // [-1000,1000]->EPS=1e-8 [-10000,10000]->EPS=1e-7
inline int sgn(const R& r){return(r > EPS)-(r < -EPS);}
inline R sq(R x){return sqrt(max<R>(x,0.0));}

const int dx[8]={1,0,-1,0,1,-1,-1,1};
const int dy[8]={0,1,0,-1,1,1,-1,-1};

// Problem Specific Parameter:
string board[55];
bool dist[55][55];

int main(void){
	int h,w;
	cin >> h >> w;

	int sy,sx,gy,gx;
	cin >> sy >> sx >> gy >> gx;
	sy--,sx--,gy--,gx--;

	rep(i,h) cin >> board[i];


	dist[sy][sx]=true;
	queue<int> q;
	q.push(sy),q.push(sx);

	while(!q.empty()){
		int cy=q.front();q.pop();
		int cx=q.front();q.pop();

		int ch=board[cy][cx]-'0';
		rep(d,4){
			const int ny=cy+dy[d];
			const int nx=cx+dx[d];

			if(ny<0 or h<=ny) continue;
			if(nx<0 or w<=nx) continue;

			int nh=board[ny][nx]-'0';
			if(abs(nh-ch)>=2) continue;
			if(dist[ny][nx]) continue;
			dist[ny][nx]=true;
			q.push(ny),q.push(nx);
		}

		rep(d,4){
			const int ny=cy+2*dy[d];
			const int nx=cx+2*dx[d];

			if(ny<0 or h<=ny) continue;
			if(nx<0 or w<=nx) continue;

			int nh=board[ny][nx]-'0';
			int mh=board[ny-dy[d]][nx-dx[d]]-'0';
			if(nh!=ch) continue;
			if(mh>ch) continue;
			if(dist[ny][nx]) continue;
			dist[ny][nx]=true;
			q.push(ny),q.push(nx);
		}
	}

	if(dist[gy][gx])
		puts("YES");
	else
		puts("NO");
	
	return 0;
}